Plug-In Prius grille-blocking

That would be horribly difficult. Temp, Wind, Traffic, Lights, etc. have too much of an influence to be able to recreate circumstances for realistic comparison.

Don't forget, losing heat while you're creaping along in heavy congestion is a big deal.

 

I captured another drive last week, but didn't get time to type up my notes... there was this election distraction, ya know.

This data was my coldest collected so far, still quite warm by Minnesota standards though.

It was 29°F outside. At the 9.3 mile mark from the 17.2 mile morning commute, the engine shut off slowing down from 70 mph. The coolant temperature had got up to 166°F from that drive with EV-BOOST. That's plenty to provide heat for cabin warmth, which I wasn't actually using then. Heck, I haven't even started wearing my winter coat yet.

Anywho, what I'm most interested in is the retention of heat while driving in EV mode.From 60 to 45 mph, with a variety of traffic & stops while the speed limit drops in 5 mph increments along the way, I drove along in smooth & silent bliss. At the 16.0 mile mark, the battery-pack was depleted and the engine started back up. The coolant temperature had dropped to 109°F. The engine only ran briefly, settling at 130°F as I pulled up to the usual spot in the parking ramp using only electricity (EV in HV, also known as Stealth mode).

The final result was 153 MPG. That's still pretty darn good.

When the real cold arrives, then things will get interesting.

 

Actually, I'm one of the biggest promoters of "Just drive it." That means don't do anything special when you're behind the wheel. For my experiments with pushing the HV/EV toggle to manually trigger the engine rather than allowing it to start on it's own, that proved to be of little to no benefit for my 16.7-mile commute.

Prepping a vehicle for winter is an entirely different matter. You should always make sure everything under the hood is up to snuff, as well as tires, and protection for the paint. Of course, that applies to all vehicles of all makes & kinds. The recommendation of taking 20 minutes out of your schedule once every 365 days and spending $2 is hardly a major inconvenience. In fact, that used to be a standard practice 20 years.

Keep in mind that heater use is different. You still have a choice of ECO, Normal, and EV modes... which all affect cabin warming. Your selection of temperature & fan do too.

 

Today's drive took on a different approach.

Even though it's still to warm for the heater yet (40°F this morning), I wanted to see how much of an influence it would have on coolant temperature in the mild conditions. So, I turned it on with a setting of 75°F and the fan on low with blower settings for window & foot.

At the usual 9.3 mile mark, upon switching from EV-BOOST to EV mode, the engine had heated up the coolant to 157°F. That's a little below the 166°F expected without the heater on.

At the 13.4 mile mark, the coolant temperature was just about to drop to 114°F degrees. Since I was quite warm, didn't want the engine to start up, and there was still 3.1 miles of EV remaining, I shut off the heater.

To my delight, I arrived at the usual parking spot with 0.1 EV still. That was sweet! At a total distance of 16.7 miles, the coolant had dropped to 100°F. The result was an average of 184 MPG.

Now I'm well prepared for seeing what happens when the daily high is well under the freezing point. Of course, the basis of comparison will be difficult... since driving conditions can change dramatically. I've seen MPG climb when up due to heavily snow congested traffic with my 2010. Now having plugged-supplied electricity available, winter results will be very exciting to witness and a fascinating comparison with the 2010 data I collected along that same commute, also with grille blocking.

 

The discovery process is what I look forward to.

Today was an good example... much like yesterday's morning commute; however, I arrived at the parking spot with 194 MPG average and 0.7 EV remaining still. That was an expected improvement.

My guess is the wind must have been more of an influence than I've ever noticed in the past. After all, I usually don't observer detail as I have been lately.